We propose to test the efficacy of an intervention designed to prevent obesity in low-income, Mexican American children. Mexican-American children are more obese than other minority groups in the U.S. population, and are the fastest growing minority group in the U.S.A. Poor dietary practices, especially food habits that are acquired as families acculturate to the American food supply, are thought to be associated with children's excess weight gain. We propose to conduct a randomized clinical trial in which 250 families receive family-based behavioral counseling (FBC) sessions and 250 families receive an active placebo control intervention. Mothers and their second or third grade children from sixteen low-wealth elementary schools will be randomized into either the treatment or control interventions. The purpose of the FBC sessions is to change children's food environment. Specifically, we intend to increase the amount of fruit and vegetables, and decrease the amount of high fat foods available to children in their homes. In addition, we will encourage parents to model healthy dietary practices for their children. Two intervention strategies, a video, "What's to Eat?" designed specifically for this population, and photographs of each family's food practices, taken by family members, will be used in the counseling sessions. The control intervention will consist of group sessions using a curriculum that adapts the standard nutrition recommendations to traditional Mexican-American foods. Community health advisors will conduct the both the FBC and control sessions. The primary outcome of the trial is children's BMI. The secondary outcome is household food supplies. We hypothesize that within a one year timeframe, children's whose mothers are exposed to the FBC will have lower BMI's compared to children whose mothers receive the active placebo control intervention. The mechanism through which we intend to change weight status is altering the type of foods available to children in their homes. Therefore, two household food inventories, one collected prior to and one after the family's payday will be used as secondary outcomes. In addition, mothers' reports of household food security level, food purchase motives, and family food interaction will be collected as covariates. Measurements will be collected within one month of completing the interventions and at six months and one year follow-ups.